Constituents with DNA topoisomerases I and II inhibitory activity and cytotoxicity from the roots of Rubia cordifolia.

Activity-directed isolation of the ethyl acetate fraction from the roots of Rubia cordifolia resulted in the identification of a new anthraquinone, 1,3,6-trihydroxy-2-hydroxymethyl-9,10-anthraquinone-3- O- α- L-rhamnopyranosyl-(1 → 2)- β-D-(6'-O-acetyl)-glucopyranoside (1), two new dihydronaphtoquinones, 1,4-dihydroxy-2-carbomethoxy-3-prenylnaphthalene-1-O- β-D-glucopyranoside (2) and mollugin-1-O- β- D-glucopyranoside (3), and a new monoterpenoid, 3 R,3a S,4 R,6a R-3,4,6-tris(hydroxymethyl)-3,3a,4,6a-tetrahydro-2 H-cyclopenta[ B]furan-2-one (4), together with nine known compounds (5-13). The structures of these compounds were elucidated on the basis of spectroscopic evidence. In addition, their DNA topoisomerases I and II inhibitory activity and cytotoxicity were measured.